The present invention is directed to a device used in threading thick-walled tubing. More particularly, the present invention is directed to a machine for coning and threading the end of a length of high-pressure (>10,000 psi) tubing to enable it to be joined to an adjacent length of tubing or fittings including tees, crosses, elbows, and valves.
The present invention relates to preparing high-pressure tubing (generally stainless steel) for connection using a collar by coning and affixing, by way of example and not limitation, a left-handed thread. High-pressure tubing is used in support equipment for the oil and gas drilling industry, and is also utilized in water jet, water blast, and other industries as well. While coning and threading is fairly easy for ¼″ OD tube stock, a machine is needed for tube OD's from ⅜″ though 1″. The coning and threading machine of the present invention provides for coning, facing, and threading from one end of the machine in one setup operation. Existing coning and threading machines feature a coning head on one end and a threading end on the other. This requires significant manipulation of the high-pressure tubing being machined which is particularly problematic when the attempt is being made in a crowded machine shop with 20′ lengths of tube.
The present invention permits the length of tube to be chucked once, coned and threaded without the need for extensive (or actually, any) repositioning of the workpiece. The machine of the present invention comprises a) a collet for receiving a first end of the length of the high-pressure tubing and holding the workpiece aligned with a first axis; b) a coning head for forming a taper on the first end of the tubing; c) a threading head for creating a thread length on the outside diameter on the first end; whereby the first end of the tubing can receive the taper from said coning head, and the thread length from said threading head while engaged in said collet. In the first embodiment, the coning head and the threading head are co-planar and, in fact, ride on a common carriage.
The machine of the present invention includes a first displacement means to move the carriage laterally between a plurality of positions and a second displacement means to move the carriage longitudinally along the first axis. A fixed stop on the machine controls a longitudinal distance the carriage can move. The invention can accommodate a plurality of sized coning blades which are installed in the coning head to accommodate a plurality of diameters of high-pressure tubing. In point of fact, 9 sizes of coning blades are available for each machine. A thread control knob adjusts to one of a plurality of thread lengths for particular diameters of high-pressure tubing. A large removable chip bucket catches metal chips removed during coning and threading operations. Coolant is supplied through the shafts supporting the coning and threading heads. Coolant is also captured in the chip bucket and recirculated to the shafts via a submersible pump.
Various other features, advantages, and characteristics of the present invention will become apparent after a reading of the following detailed description.